Gerard beekman



(No Model.)

G. BEEKMAN. PROPELLING MECHANISM FOR BIGYGLES. No. 582,974.

Patented May 18. 1897.

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m: Nonms rcnzps o0. morn-Lima. wummnon n c UNITED STATES T FFICE.

GERARD BEEKMAN, on NEW YORK, N. Y.

PROPELLING MECHANISM FOR BICYCLES.

SPECIFICATION forming part of Letters Patent No. 582,974, dated May 18,1897.

Application filed February 4,1897. Serial No. 621,9d5. (N0 model.)

To (LZZ/ whom, zit-12m. concern/.-

Be it known that I, GERARD BEEKMAN, a citizen of the United States, anda resident of New York, in the county of New York and State of New York,have invented certain new and useful Improvements in PropellingMechanism for Cycles, of which the following is a specification.

My invention relates to improvements in bicycle-propelling mechanismwherein the motion of the pedal-cranks is imparted to the sprocket-wheelor other driven element by means of an automatic clutch mechanism inwhich the clutch action is produced intermittently by the pressure orimpulses of the riders feet upon the pedals, and in which coasting,braking, or back-pedaling, as well as propelling, may each be effectedaccording to the manner of moving or arresting the pedal-cranks andwithout requiring the feet to be removed from them.

The object of the invention is to provide a simple, effective, anddurable means of producing the clutch action by the pressure of the feeton the pedals and to obtain positive propulsion and controllablebrake-pressure in the clutch action and to provide a selfcontained andneat appearing construction.

My invention consists in certain novel features and combinations ofparts hereinafter described and claimed wherein the pedal cranks areflexibly connected with relation to each other, so that their movementof flexure for actuating the clutch occurs on their axis of rotation;also wherein the elastic means tending to support said cranks indiametrically opposite relation is located on their axis of rotation;also wherein the construction of the friction-clutch device itself isimproved and simplified, and also wherein a compound friction andpositive clutch mechanism is used.

Referring to the accompanying drawings, Figure 1 is a horizontal sectiontaken at so as, Fig. 2, showing the crank-shaft hanger and crankmechanism embodying my improvements adapted to the frame of arear-driven bicycle. Fig. 2 is a vertical section taken at g y, Fig. 1.Fig. 3 is a detail sectional View of the crank-boss, taken at .2, Fig.4; Fig. 4, an inside elevation of the crank-boss; Fig. 5, a top planview of the connecting-fork for guiding the movable parts of thefrictionclutches, (the position corresponding to Fig. 1;) Fig. 6, aninside face View of said fork; Fig. 7, a top plan View ofthespring-collar, one of which is connected to each end of the torsionalspring. Fig. 8 is a face view of said collar; and Fig. 9 is a verticalsection through the crank-boss, showing the clutchcam, the fork, thecollar, the spring, and the internal shaft, which connects the forks andassists in alining the axis of the cranks.

In Figs. 1 and 2, A represents the crankshaft hanger; B, the centerbrace of the frame; 0, the front lower brace, and D the rear lowerbrace, the arrow E representing the direction in which the machine is tobe propelled.

F represents the crank-shaft, which-is tubular and is journaled inball-bearings G G and bears the sprocket-wheel, which is represented atH. For convenience the shaft F is made in two parts 1 2, which areunited by a screw threaded sleeve 3 and rotatively locked by a key 4.

The cranks I I are mounted in oppositelydisposed relation on their axisof rotation, (represented by the line J J.) Said cranks are maintainedin opposite relation through the agency of a torsional spring L, theextremities of which are firmly joined to collars M, which turn looselyon the internal shaft K to the limited extent required, and to thesecollars M the cranks I I are securely connected, the projections 5 5,Figs. 3 and 4t,which terminate the inwardly-projecting sleeve 7 of thecrank-boss, interlocking between the projections 6 6, Figs. 7 and 8, onthe collar M at each end of the device.

N represents the clutch-ring of the driven element,which ring isintegral with the tubular shaft F, carrying the sprocket-wheel H. Thering N is provided on its exterior portion with clutch-pockets 10,presenting beveled or tangent surfaces 11, as shown, and containingrollers 12,which engage between the flange 14 of the crank-boss P andsaid tangent surfaces in such manner as to engage the crank positivelywith the ring N and driven element of the machine when-the cranks arepropelled forwardly. In addition to the positive clutch thus constitutedI provide a friction-clutch which in the illustration is composed of twosegmental movable parts S S, of rawhide or other suitable material,which are adapted when expanded apart to frictionally engage on theinternal surface of the ring N.

The parts S S are actuated by means of a cam T, securely keyed orotherwise fastened to the sleeve 7 of the crank-boss P, and the cam Twill expand the clutch-pieces S S by rotative pressure in eitherdirection.

The internal shaft K has fixed thereon the guiding-forks R at each end,which project loosely through the furthermost portions 15 of the slotsbetween the projections 5 of the crank-sleeves 7, and said forks enterbetween the ends of the segments S S and guide them, so that the onepair will always be kept in a rotative position corresponding with theother pair of segments. The extremities of the shaft K are provided withround nuts 1G 17, right and left threaded, so as tolock one another andsecure the parts in position when put together, and the said nuts seaton shoulders 18 in the sleeves '7.

The cranks are maintained in alinement of axis J J by the proper contactof the peripheries of the nuts 16 17 with the countersunk holes 19, Fig.3, in the crank-bosses, and the cranks may also be steadied by contactof the flange 1t with the ring N at the points of projection between thepockets. Moreover, the innerextremities of the sleeves 7 of the cranksuniting with the collars M and interlocked or mortised together, asbefore described, and turned 01f evenly form bearin gs for the cranks inthe tubular shaft F, which serve to support the axis of the cranks.

By means of the foregoing construction it will be seen thatwhen thecranks or either of them are pressed in a forward direction of retationthe clutch on the outer side of the ring N will positively engage at theinitial part of the movement and impart propulsion.

Then the machine is running, the cranks I I may be brought to rest, therollers 12 becoming idle, and the spring L is stiff enough to supportthe weight of the riders feet for purposes of coasting or intermittentresting.

\Vhen muscular pressure is exerted upon the pedals of the cranks, thetendency is to move them simultaneously in opposite directions about theaxis J J of rotation. The spring L yielding, a limited are movement ofthe cranks relatively to one another will occur, and the cams T T willbe actuated in opposite directions to expand the clutch'picces S S,which are connected to one another on opposite sides of the machine, soas to resist relative rotative displacement, as before described, by theageney of the forks It R and shaft K. Consequently a frictionalengagement will be effected between the pieces S S and the rings N,which by the excess of backpedaling pressure of the feet on the crankswill produce a braking action. The cranks may remain stationary whilethe braking action is thus effected, or after the machine has beenstopped the same may be propelled backward by the backward rotation ofthe cranks, the clutch device S S engaging.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is-

1. In a cycle, the combination with a rotarydriven element, of tworotary pedal-cranks flexibly connected in diametrically oppositerelation to each other upon their axis of retation and having theirpivot of flexure on said axis, and clutch mechanism operated by thefiexure of said cranks whereby to engage with said driven element.

9. Ina cycle, the combination with a rotarydriven element, of two rotarypedal'cranks flexibly connected in diametrically opposite relation toeach other upon their axis of rotation, torsional elastic means locatedon said axis connecting said cranks and tending to support them in saidrelation, and clutch mechanism operated by the flexure of said crankswhereby to engage with said driven element..

3. In a cycle, the combination with a rotarydriven element, two rotarypedal-cranks flexibly connected in diametrically opposite relation toeach other upon their axis of rotation and having their pivot of flexure on said axis, of a clutch mechanism consisting indiametrieallymovable parts engaging with said driven element, and camformations connected to said cranks and upon their axis acting on saiddiametrically-movable parts so as to press them against said drivenelement by the motion of flexure of said cranks.

at. In a cycle, the combination with a rotarydriven. element, of tworotary pedal-cranks flexibly connected in diametrically oppositerelation to each other upon their axis of rotation and having theirpivot of tlexure on said axis, eachv said crank provided with twoindependent clutch mechanisms; one clutch positively engaging with saiddriven element by the initial forward-propelling rotation of a crankirrespective of its relative flexurc to the other crank, and the otherclutch frictionally and controllably engaging with said driven elementby the retardation or backward rotation of said cranks and according tothe relative flexure thereof produced or initiated by simultaneouslyopposing pressures of the feet of the rider on therespectivecrankpedals.

Signed at New York, in the county of New York and State of New York,this 2d day of February, A. I). 1897.

GERARD BEEKMAN.

Witnesses:

LUGENE Lucas, HENRY F. PARKER.

